if you follow intraday charts, then you`ll know exactly when to close your positions. You`ll know that stock will close below or above xyz levels so that you exit safely. Take example of Cipla, when it broke from 379.50, it did awfully bad to get over even 378 for quite good times, all signs were there that stock will break down, once below 376, it fell cats and dogs. If SL is near then monitoring intraday charts is must for good SL play.
My advice to u would be not to trade it,it goes up then shoot it and sit.Pl avoid going long,reasons already explained. Stocks like such crash without giving a chance to exit. If it goes up dont worry,it would come down.